1. Technical Field
The present disclosure relates to a method for manufacturing light emitting devices, and more particularly, to a method for manufacturing an LED (light emitting diode), wherein a profile of a light emergent face of the LED can be easily controlled.
2. Description of Related Art
As a new type of light source, LEDs are widely used in various applications. An LED often includes a base having a cavity defined therein, a pair of leads fixed in the base, a light emitting chip received in the cavity to electrically connect the two leads, and an encapsulant filling the cavity to seal the chip. Typically, the encapsulant is formed in the cavity by injecting an encapsulation liquid into the cavity and then heating the liquid to become cured and solid. Thus, the encapsulant becomes rigid to form a light emergent face with a predetermined shape. However, during conversion from liquid to solid, the encapsulant contracts, whereby the light emergent face is recessed. Thus, a concave light emergent face is naturally formed after the encapsulant is cured. The concave degree of the concave light emergent face is difficult to control whereby the concave light emergent face affects the light emergent angle of the LED and causes the light distribution of the LED becoming undesirable. If too much encapsulation liquid is injected into the cavity, a convex light emergent face is formed; like the naturally formed concave light emergent face, the convex degree of the naturally formed convex light emergent is difficult to control, whereby the convex emergent face also undesirably affects the optical characteristics of the LED.
What is needed, therefore, is a method for manufacturing an LED which can overcome the limitations described above.